WO2008010431A1

WO2008010431A1 - Inner blade for electric razor

Info

Publication number: WO2008010431A1
Application number: PCT/JP2007/063648
Authority: WO
Inventors: Masaaki Sato; Shunsuke Komori; Jyuzaemon Iwasaki; Takeshi Shiba
Original assignee: Panasonic Electric Works Co., Ltd.
Priority date: 2006-07-21
Filing date: 2007-07-09
Publication date: 2008-01-24
Also published as: EP2047956A4; JP2008023122A; CN101489736B; KR20090031909A; US20090307909A1; EP2047956A1; CN101489736A; RU2423226C2; RU2009102520A; EP2047956B1; JP4775152B2

Abstract

An inner blade (5) for an electric razor having blades (30) supported by a base (20). When the inner blade (5) is reciprocated in parallel with the outer blade (10) having whisker introducing holes (11), whiskers are cut between the inner blade (5) and an outer blade (10). The blades (30) are arranged in parallel with each other, and a pair of blade edges (32) is symmetrically arranged on both sides of the upper part (31) of each blade (30). The blade edges (32) are defined by the upper surface (31) and scoop surfaces (33) tilted relative to the upper surface (31). The tip of each blade edge (32) is rounded to a shape with a curvature radius R (μm) and is formed such that the curvature radius R satisfies the relationship of R ≤ -0.2 α + 1.1 (μm), with α being the angle in degree of a scoop surface (33) relative to the upper surface (31).

Description

Specification

Inner blade for electric razor

Technical field

TECHNICAL FIELD [0001] The present invention relates to an inner blade for an electric razor, and more particularly, to an inner blade provided with a plurality of parallelly arranged blades used for a reciprocating drive type electric razor.

Background art

[0002] An electric razor cutting head is composed of an outer blade having a large number of scissors-introducing holes and an inner blade having a plurality of blades, and the inner blade is connected to a drive source and is connected to the outer blade. Are driven back and forth.

[0003] For example, the blade 30 used in the conventional inner blade described in Japanese Patent Laid-Open No. 6-142347 has an undercut on the side surface near its upper end, as shown in FIGS. 11A and 11B. The blade edge 32 has a predetermined angle. When cutting the scissors, the scissors H introduced from the scissor introduction hole 11 formed in the outer blade 10 is sandwiched between the blade edge of the outer blade 10 and the blade edge 32 of the upper end of the blade 30, and the blade 30 is inserted. Cut 髭 H by moving it parallel to the outer blade 10.

[0004] As shown in FIG. 11A, it is assumed that 髭 H is introduced into the central portion of heel introduction hole 11.髭 As the blade 30 moves, the blade H is pushed down by the blade edge 32 of the blade 30 until it reaches the blade edge of the outer blade 10 and reaches the blade edge of the outer blade 10 as shown in FIG. In this state, the pressed heel H is sandwiched between the cutting edge of the outer blade 10 and the cutting edge 32 of the blade 30 and cut. For this reason, as shown in FIG. 11C, there is a problem that the tip portion of the heel H cut in a pushed state is slanted and the finished heel H is short and cannot be finished.

[0005] In order to solve the above-mentioned problems, WO2003Z016000 proposes that when cutting 内 H introduced into the central portion of 髭 introducing hole 11, 髭 H that does not push down 髭 H is a blade of the inner blade. An inner blade that can be cut only by 30 is disclosed.

[0006] FIG. 12A and FIG. 12B [As shown here] This WO2003 / 016000 [Indicated blade 30 has a pair of cutting edge 32 provided on both sides of the upper portion of blade 30. . this The blade edge 32 is defined by the upper surface of the blade 30 and a rake face inclined with respect to the upper surface. The tip of the edge 32 is rounded to have a radius of curvature R (m), and the radius of curvature R of the edge of the edge 32 is R <-0. 067 · The edge angle α is set to satisfy the relationship of +4.7 (m).

[0007] As shown in FIG. 12A, the heel H introduced into the central portion of the heel introduction hole 11 does not reach the cutting edge of the outer blade 10 because the force starts to move with the operation of the blade 30 of the inner blade. From the inside, the inner blade 30 starts cutting the force near the root. However, as it is cut only by the blade 30, the heel H that is inertially supported by the skin S is pushed by the cutting edge 32 of the blade 30 and is cut while being slightly inclined as shown in FIG. 12B. As a result, although it is cut shorter than that of the conventional example shown in JP-A-6-142347, as shown in FIG. In FIG. 12C, the height of the inclined portion indicated by the symbol h corresponds to the amount that 髭 H extends over several hours. In order to cut the cut surface so as to be substantially perpendicular to the protruding direction of 髭 H at the base portion of 髭 H, it was necessary to repeatedly perform cutting with blade 30 several times.

Disclosure of the invention

[0008] The present invention has been made to solve the above-described problems of the conventional example, and it is possible to cut the base portion of the ridge so as to be substantially perpendicular to the protruding direction of the ridge. An object is to provide an inner blade for an electric razor.

[0009] An inner blade for an electric razor according to an aspect of the present invention includes a plurality of blades supported by a base, and is reciprocally driven in parallel with an outer blade having a flange introduction hole. A plurality of blades are arranged parallel to each other, a pair of blade edges are provided symmetrically on both sides of the upper portion of each blade, and the blade edges are formed on the upper surface of the blade, It is defined by a rake face inclined with respect to the upper surface, and the tip of the cutting edge is rounded to have a radius of curvature (Rm). The radius of curvature R is set so as to satisfy the relationship R≤—0.02 · blade angle K ^ m).

[0010] According to such a configuration, when cutting the scissors, the scissors introduced into the central portion of the scissors introduction hole of the outer blade start to move in accordance with the operation of the blades of the inner blade. Reaching the edge of the blade The cutting of the force near the root is started by the inner blade. Since the radius of curvature R of the tip of the blade edge edge edge is set to be smaller than that of the conventional example shown in the above-mentioned WO2003Z016000, the cutting is continued without tilting the wrinkles. As a result, it is possible to cut the cutting surface so that the cutting surface is substantially perpendicular to the protruding direction of the ridge at the base portion of the ridge, and to cut the ridge short without repeatedly cutting as in the conventional example. Can do.

Brief Description of Drawings

FIG. 1 is a diagram showing a schematic configuration of an electric razor using an inner blade for an electric razor according to the present invention.

FIG. 2 is a side view showing the configuration of the inner blade for an electric razor according to one embodiment of the present invention.

FIG. 3 is a cross-sectional view showing the shape of a blade constituting the inner blade.

FIG. 4A, FIG. 4B and FIG. 4C are explanatory diagrams showing how to obtain the radius of curvature of the edge of a blade having a different shape.

[FIG. 5] FIG. 5 is a graph showing the relationship between the blade edge angle and the radius of curvature of the blade edge edge that satisfy the condition that the cutting resistance is 0.2 (N) or less.

FIG. 6 is a graph showing the relationship between the radius of curvature R of the tip and the cutting resistance when the edge edge angle ex is changed.

[FIG. 7] FIG. 7 is a graph showing the relationship between the scissor cutting resistance and the scissor cutting surface angle Θ.

[FIG. 8] FIG. 8 is an explanatory view for explaining the definition of the heel cutting plane angle Θ.

FIG. 9A and FIG. 9B are explanatory diagrams showing the cutting process of the scissors by the inner blade, respectively.

FIG. 10 is a cross-sectional view showing an example in which a hardened layer is provided on a blade.

FIG. 11A, FIG. 11B, and FIG. 11C are explanatory diagrams showing problems when the scissors are sandwiched between the edge of the outer blade and the edge of the blade in the conventional example.

FIG. 12A, FIG. 12B, and FIG. 12C are explanatory views showing problems in cutting the scissors with only the inner blade in each of the other conventional examples.

BEST MODE FOR CARRYING OUT THE INVENTION

[0012] An inner blade for an electric razor according to an embodiment of the present invention will be described with reference to the drawings. Light up. As shown in FIG. 1, the inner blade 5 of the electric razor according to the present invention is applied to a reciprocating electric razor 1, and is arranged on a synthetic resin base 20 in parallel to each other. A plurality of blades 30 are provided. The reciprocating drive type shaver 1 has a drive mechanism 2 composed of a motor or the like housed in a housing 4 and a rechargeable battery 3, for example. The base 20 of the inner blade 5 is coupled to the drive mechanism 2, whereby the inner blade 5 is held in a state where the upper end portion of the housing 4 protrudes outward. The outer blade 10 has a large number of soot-introducing holes 11 formed substantially uniformly, and the outer blade 10 is attached to the upper end of the housing 4. The inner blade 5 is reciprocally driven in parallel with the outer blade 10 by the drive mechanism 2, and the blade caught in the rod introduction hole 11 is cut by the blade 30. The force housing 4 (not shown) is formed in a shape that can be easily held by the user's hand.

As shown in FIG. 2, each blade 30 is formed to be bent in an inverted U shape, and both ends thereof are fixed to the base 20. A blade edge 32 is formed in a central arcuate portion of the blade 30 over a predetermined angular range X (for example, about 100 degrees), and the arcuate portion extends along the lower surface of the outer blade 10 curved in a similar shape. And slide.

As shown in FIG. 3, a rib 34 is formed at the center of the lower surface side of the blade 30 so as to protrude downward, and the upper edge force of the rib 34 also protrudes with a cutting edge 32 laterally. The blade edge edge 32 is formed (regulated) between the upper surface 31 of the blade 30 and the rake face 33 inclined with respect to the upper surface 31, and the tip of the blade edge 32 has a curvature radius R (unit: / zm). The radius of curvature R of the edge of the cutting edge is R≤—0.02 · the cutting edge angle 1 (m) as the angle α (unit: degree) of the rake face 33 with respect to the upper surface 31. Is set to satisfy

[0015] By the way, the cutting edge 32 is often shaped as shown in FIGS. 4A to 4C depending on the degree of finishing. Therefore, the curvature radius R of the cutting edge 32 defined in the present invention was obtained by approximation from the effective minimum thickness L of the cutting edge (R = LZ2). That is, for the shapes shown in FIGS. 4 (a) to 4 (c), it passes through the extension line of the rake face 33 and the inflection point V on the blade edge 32 side of the upper surface of the blade 30, and the rake face 33 The distance between the extension line and the parallel line is regarded as the effective minimum length L, and the radius of curvature R is defined as R = LZ2.

Next, as shown in FIG. 8, the angle formed by the cut surface with respect to the protruding direction of the heel H from the skin S is determined. 髭 Cut plane angle Θ (unit: degree) is defined. The blade edge angle α (unit: degrees) and the curvature of the tip of the blade edge 32 so that the 髭 cutting surface angle Θ is almost perpendicular to the protruding direction of 髭 H, that is, the 髭 cutting surface angle is 85 degrees or more. The relationship of radius R (unit: / zm) was obtained.

First, the cutting edge angle α was set to various angles, and the relationship between the cutting resistance (unit: Ν) and the radius of curvature _R (unit: ^ m) of the cutting edge edge was obtained by experiments. In the experiment, the relationship between the radius of curvature R of the edge of the edge of the blade edge and the scissor cutting resistance was obtained for each of the blade edge angles α = 15 °, 30 °, 45 ° and 60 °. The results are shown in Fig. 6. As shown in FIG. 6, when the blade edge angle α is constant, the smaller the radius of curvature R at the edge of the blade edge, the smaller the cutting resistance. In addition, when the radius of curvature R of the tip of the cutting edge is constant, the smaller the cutting edge angle, the lower the cutting resistance.

[0018] Next, when the two parameters of the cutting edge angle α and the radius of curvature R of the edge of the cutting edge are replaced with the cutting resistance, the relationship between the cutting resistance and the cutting plane angle Θ was obtained. The results are shown in Fig. 7. The cutting speed of the inner blade of a general electric razor is 0.5 m / sec or more (that is, the cutting speed of the slowest inner blade of a general electric razor is about 0.5 mZ second). The cutting speed of the inner blade was set to 0.5mZ seconds, and the ridge was cut o

[0019] Through experiments, the height h (unit: mm) of the inclination due to the cutting of 髭 H when the heel cutting surface angle was 0 force, 85 °, 80 °, 70 °, and 60 ° was obtained. The results are shown in Fig. 7. H = 0 (mm) for Θ = 90 °, h = 0.001 (mm) for 85 °, h = 0.03 (mm) for Θ = 80 ° In the case of 70 °, h = 0.06 (mm), and in the case of Θ = 60 °, h = 0.09 (mm). By the way, in general, it takes 2 hours to grow 0.03 mm, 4 hours to grow 0.06 mm, and 6 hours to grow 0.09 mm. Therefore, if Θ = 80 °, 2 hours of heel elongation is left unshaved, if Θ = 70 °, 4 hours of heel elongation is left unshaved, and if Θ = 60 ° 6 hours of the amount of growth will be left unshaved. Therefore, if Θ is not 85 ° or more, it will be unpreferable that an unshaved portion of 髭 H will be left for one hour or more.

[0020] As is apparent from FIG. 7, the condition for the heel cutting surface angle Θ force ¾5 ° or more is It can be seen that the resistance is 0.2 (N) or less. In other words, if the heel cutting resistance is 0.2 (N) or less, the heel cutting surface angle Θ force is ¾5 ° or more, and the heel H is cut so that it is substantially perpendicular to the protruding direction. I understand.

[0021] This satisfies the conditions of the cutting edge angle oc and the radius of curvature R of the tip of the cutting edge 32 that are included in the region where the cutting resistance is 0.2 (N) or less in FIG. 6 (hatched region in FIG. 6). If the inner blade is provided with the blade 30, it means that the heel H can be cut so that the heel cutting surface angle Θ force is ¾5 ° or more.

[0022] Therefore, the present invention pays attention to the fact that when the scissor cutting resistance is 0.2 (N) or less, the scissor cutting surface angle Θ force is ¾5 ° or more, and the scissor cutting resistance is 0.2 (N). The relationship between the edge angle α (unit: degree) satisfying the following and the curvature radius R (unit: m) of the tip of the edge 32 is obtained. This can be expressed as R≤—0.02 · cutting edge angle a + 1.1 (m). This is shown in Fig. 5.

In other words, in FIG. 5, the edge angle ex included in the region below the line indicated by R≤—0.02 · the edge angle a + 1.1 (m) and the tip of the edge 32 of the edge If the inner blade has a blade 30 that satisfies the condition of the radius of curvature (Rm), as shown in FIGS. 9A and 9B, it is 髭 H introduced into the central portion of the 髭 introduction hole 11 when cutting 髭 H. However, the force that starts moving with the movement of the blade 30 of the inner blade Before the blade edge of the outer blade 10 reaches the cutting edge, the blade 30 starts cutting from the vicinity of its base, Cutting continues without tilting. As a result, the cutting surface of 内 H is substantially perpendicular to the protruding direction of 髭 H from the skin S at the root portion of 髭 H by only the inner blade 30 (that is, the cutting surface angle is 85 ° or more). It is possible to cut the wrinkles so that they can be cut as many times as in the conventional example.

[0024] Since the cutting resistance decreases as the cutting speed of the inner blade increases as described above, the cutting resistance is further reduced when the cutting speed of the inner blade is 0.5 mZ seconds or more. It is clear that the above relationship is satisfied. As a result, in all of the electric razors having a general cutting speed, the cutting surface of 髭 H should be cut substantially perpendicular to the protruding direction (cutting surface angle is 85 ° or more) with only the inner blade. Can do.

[0025] As can be seen from FIG. 6, when the blade edge angle a = 60 °, the scissor cutting resistance is 0.2 ( N) The cutting edge angle α <60 °, preferably α ≦ 45 °, since it is not less than or equal to N).

[0026] Further, the lower limit value of the cutting resistance (は) is not particularly limited, but considering the manufacturing restrictions of the blade 30, 0.02 (Ν) or more is preferable.

Incidentally, as shown in FIG. 3, the cutting edge 32 on both sides of the upper surface of the blade 30 has a protrusion amount Ρ from the rib 34 of 0.05 mm or more. This is based on the following reason. The diameter D of a typical ridge H is about 0.1 mm. As shown in Fig. 3, when cutting 髭 H at the cutting edge 32 of the blade 30, the rib 34 does not hit 髭 H until 髭 H is cut by 1Z2 or more in the diameter direction. In order to prevent 34H from falling down when the rib 34 is pressed against 髭 H before H is cut by 1Z2 or more, the protrusion amount P from the rib 34 of the cutting edge 32 on both sides of the upper surface of the blade 30 is 0.0.05mm or more is required. By satisfying this condition, after cutting 髭 H in the diameter direction by 1Z2 or more, the rib 34 hits 髭 H, so that it can be cut without tilting 倒 H.

In addition, as shown in FIG. 10, a hardened layer 35 may be formed on the rake face 33 that forms the cutting edge 32. As a result, wear of the cutting edge 32 can be prevented and the sharpness can be maintained for a long period of time. The hardened layer 35 can be formed, for example, by overlaying a clad material such as Ti or A1 on the material of the blade 30 and integrating them. Alternatively, the hardened layer 35 can also be formed by subjecting the surface of the material of the blade 30 to heat treatment such as laser quenching or impact quenching. Further, it can be formed by coating the surface of the material of the blade 30 with TiN, TiC, CrN, hard carbon film or the like. Further, the hardened layer 35 may be formed on the upper surface 31 of the blade 30 in addition to the rake surface 33.

[0029] It should be noted that the blade used for the inner blade according to the present invention can be applied to an inner blade of another type of electric razor that is not limited to a reciprocating drive type electric razor. By being formed, it is possible to improve the cutting effect of the wrinkles.

[0030] This application is based on Japanese Patent Application 2006-199953, and the contents thereof should be incorporated into the present invention as a result by referring to the specification and drawings of the above-mentioned patent application.

[0031] The present invention has been sufficiently described by the embodiments with reference to the accompanying drawings. However, it will be apparent to those of ordinary skill in the art that various changes and modifications are possible. Therefore, such changes and modifications should be construed as being included in the scope of the present invention without departing from the scope of the present invention.

Claims

The scope of the claims

[1] 1. It has a plurality of blades supported by the base, and is reciprocated in parallel with the outer blade having the heel introduction hole to cut the heel from the outer blade.

The plurality of blades are arranged parallel to each other;

The pair of cutting edge is provided symmetrically on both sides of the upper part of each blade, the cutting edge is defined by the upper surface of the blade and a rake face inclined with respect to the upper surface,

The tip of the cutting edge is rounded to have a radius of curvature (Rm), and the curvature radius of the cutting edge of the cutting edge is defined as an angle α (degree) of the rake face with respect to the upper surface.

R≤— 0. 02 · Blade angle a + l. L m)

An inner blade for an electric razor, characterized in that it is set to satisfy the above relationship.

[2] 2. It is formed so that a rib protrudes downward in the center of the lower surface side of the blade, and the edge of the blade protrudes laterally from the upper end of the rib,

2. The inner blade for an electric razor according to claim 1, wherein a protruding amount P of the blade edge on both sides of the upper surface of the blade from the rib is 0.05 mm or more.

[3] 3. The inner blade for an electric shaver according to claim 1, wherein a hardened layer is formed on a rake face forming the edge of the blade edge.

4. The inner blade for an electric shaver according to claim 3, wherein a hardened layer is also formed on the upper surface of the blade that forms the edge of the blade edge.